“Add document” link missing for users receiving access through AD groups

Question

So, using SP Foundation 2010, we've chosen to assign Active Directory groups to various sites and folders to control access, instead of assigning indidual users directly, then control all access through AD. While implementing this, I have discovered that users which have been switched to receiving contribute access exclusively through AD group assignments can't see the "Add document" link. They still have acess to upload and such, but how to do so is not as obvious or user friendly as the quick link. Anyone know how to fix this link's visibility?